.nav{
	position: fixed;
	z-index: 999;
	left: 0;
	bottom: 0;
	width: 100%;
	height: 45px;
	background-color: #fff;
	border-top: 1px solid #ccc;
}
.nav ul{
	width: 100%;
	height: 100%;
}
.nav ul li{
	width: 25%;
	height: 100%;
	float: left;
	text-align: center;
}
.nav ul li img{
	margin-top: 4px;
    width: 40px;
    height: 40px;
}